|Start Page Number:||507|
|End Page Number:||526|
|Publication Date:||Oct 2017|
|Journal:||Journal of Scheduling|
|Authors:||Boysen Nils, Stephan Konrad|
|Keywords:||scheduling, combinatorial optimization, optimization, vehicle routing & scheduling, allocation: resources, programming: travelling salesman, programming: multiple criteria|
An efficient container transfer in railway yards is an important matter to increase the attraction of rail‐bound freight transport. Therefore, the scheduling of gantry cranes transferring containers between freight trains and trucks or among trains received a lot of attention in the recent years. This paper contributes to this stream of research by investigating the computational complexity of crane scheduling in these yards. Scheduling the transfer of a given set of containers by a single crane equals the (asymmetric) traveling salesman problem in its path‐version. In railway yards, however, all container positions are located along parallel lines, i.e., tracks, and we face special distance metrics, so that only specially structured problem instances arise. We classify important problem settings by differentiating the transshipment direction, parking policy, and distance metric. This way, we derive problem variants being solvable to optimality in polynomial time, whereas other cases are shown to be NP‐hard.